Fix block-carried payload votes discarded on late envelopes

[NikhilSharmaWe]

Description

Block import discarded Gloas index-1 (payload_present) attestations when fork choice returned PayloadNotReceived because the envelope had not arrived yet. Those votes were swallowed as InvalidAttestation and never retried; envelope import only flipped payload_received.

Park block-carried votes inside fork choice when AttestationFromBlock::True hits PayloadNotReceived, then apply (or slot-queue) them from on_payload_envelope_received. That is the same path production and the harness use, so the drain cannot be skipped. Gossip still errors on PayloadNotReceived and keeps using the existing reprocess queue / UnknownPayloadEnvelope path.

Prune parked entries when the attested block leaves the proto-array. Parked votes are not persisted across restart (same class as other short-lived FC queues today) and are not deduped.

Fixes #10088

Test plan

• cargo check -p fork_choice -p beacon_chain
• cargo nextest run -p beacon_chain --features spec-minimal --release gloas_block_carried_payload_votes_applied_after_envelope

[dapplion]

we don't do such hooks in lighthouse

[NikhilSharmaWe]

Dropping the hooks, parking these on a BeaconChain pending map instead and applying them when the envelope imports.

[dapplion]

🤖 automated (dapplion's agent): Suggestion: park the votes inside fork_choice, not on BeaconChain — prototype dapplion@c2e3294, +81/−13 in one file vs +283/−4 across six. Gossip already parks this condition keyed by block root; the block path is the only gap. Separately, the drain in import_execution_payload_envelope is untested: the harness calls on_payload_envelope_received directly, so deleting it keeps the tests green.

[NikhilSharmaWe]

agreed on the coverage hole with process_envelope.

I'm going to move park/drain into fork_choice as in your prototype: park QueuedAttestation on AttestationFromBlock::True + PayloadNotReceived, drain in on_payload_envelope_received, prune with contains_block. It will be a cleaner approach.

Will remove the BeaconChain pending map

[NikhilSharmaWe]

@michaelsproul would like to know your thoughts on this, too.